Conventional car audio equipment or other electronic apparatuses often have a seesaw-type operation button. FIGS. 11 and 12 show a conventional example, electronic apparatus 101. The electronic apparatus 101 comprises an operation button 103, a button holding member 105, and a substrate 107. The operation button 103 is held by the button holding member 105 so as to be tiltable to both sides. When the operation button 103 tilts, a switch 109a or 109b on the substrate 107 is pushed. The switches 109a and 109b are provided on both sides of the tilt center of the operation button 103. A configuration of this type is disclosed, for example, in Japanese Patent Laid-Open Application No. 7-211195 (FIGS. 1 and 2).
More particularly, the tilt structure of the operation button 103 is realized by a rotation structure comprising: a pivot portion 111 of the operation button 103; and a bearing portion 113 of the button holding member 107. The operation button 103 is tiltably held by the pivot portion 111 as a tilt fulcrum. The operation button 103 also has operating portions 121a and 121b on both sides of the tilt fulcrum. The operating portions 121a and 121b are portions to be pushed by an operator. Pressing portions 123a and 123b protrude from the operating portions 121a and 121b toward the switches 109a and 109b, and the tips of the pressing portions 123a and 123b are in contact with the switches 109a and 109b. When the operating portion 121a is pushed and the operation button 103 tilts, the pressing portion 123a presses the switch 109a. When the operating portion 121b is pushed and the operation button 103 tilts, the pressing portion 123b presses the switch 109b. 
The electronic apparatus 1 has protrusions 125a and 125b as a configuration for locating the operation button 103 in a predetermined position (home position) in FIG. 11 in a neutral state where the operation button 103 is not operated. The protrusions 125a and 125b are provided on an edge portion of a button accommodating hole in the button holding member 105, and extend from both sides to the back of the operation button 103. When the operation button 103 is pushed by an operator and tilts, the protrusion 125a (or the protrusion 125b) on the pushed side bends and elastically deforms. And then, when the finger of the operator leaves the operation button 103, the form of the protrusion 125a (or the protrusion 125b) is restored, and the operation button 103 returns to the original predetermined position.
In the conventional electronic apparatus, however, since the tilt structure is made up of the pivot portion 111 and its bearing portion 113, the structure of the forming mold is complicated. Every component requires high precision, so it would not be easy to manufacture.